1. Field of the Invention
The field of the invention is Radio Frequency Identification (RFID) and in particular an RFID enabled consumer oriented system which protects consumer privacy.
2. Background
Radio Frequency Identification (hereinafter “RFID”), is a technology powered by small, wireless devices known as tags or transponders which can automatically track physical objects, animals and people when air interfacing with RFID readers, also known as interrogators. RFID can be seen as a means to explicitly label objects, animals and people so that tracking becomes automatic for back end computer host systems. Generally, in the RFID industry, an RFID tracking device which is known alternatively as a tag or as a transponder, is attached to or embedded in a product or product packaging and is air interfaced by radio frequency transmission with the antenna of an RFID reader/interrogator. The microchip itself can be as small as a grain of sand. The expense and size of a standard RFID tag or transponder package is a product of the external antenna which needs to be large enough to resonate at multiples of the wavelengths of currently authorized RFID frequencies. The antenna is usually constructed of copper or aluminum which is an expensive commodity. The authorized resonant frequencies for the antenna are Low Frequency in the 124 kHz to 135 kHz range. These have read distances of roughly two feet. There are High Frequency tags in the 13.56 MHz range with read ranges of over three feet. Moreover, there are Ultra High Frequency tags in the 860 MHz-960 MHz which have read parameters of up to 100 feet and more. RFID is being vigorously touted as a successor to optical barcode technology ubiquitous to consumer products. There are two advantages which RFID technology holds over the current barcode product identification system. First, the barcode indicates the type of object on which it is printed. For example, it will indicate to a cash register or check out automated system that the object in question is a yellow pencil of ABC brand. The RFID system goes a step further in that it emits a unique serial number which distinguishes it among millions of identically manufactured ABC brand of pencils. This unique identifying number can act as a direction finder to database entries which contain a plethora of transaction histories for individual product items. Second, barcodes are optically scanned with laser light which requires line of sight contact with readers in order for the scanning technology to operate properly. This usually means human intervention to carefully position the object to be scanned. RFID technology does not require line of sight to operate properly. It can scan hundreds of items per second. For example, a fast moving conveyor belt in a factory can be scanned for objects of interest with no need for line of sight contact.
In a supply chain application RFID is becoming ubiquitous in the tracking of crates and pallets. These are considered to be discrete, but bulk (not item level), quantities of objects. Tracking in the supply chain scenario is concerned with improving accuracy and timeliness of information regarding the whereabouts and movement of goods which comprise any specific supply chain.
In attempting to keep costs to a minimum RFID tags which are manufactured according to Electronic Product Code (hereinafter “EPC”) standards carry extremely limited on board memory. Normally, the only information on the EPC tag is the unique number as well as the usual informational data of a barcode. There can also be a link to database records for any specific tag. Although the EPC tag can be up to 96 bits in data or informational length, the centralized host database can have unlimited entries or cryptographic security algorithms regarding any specific tag in question. Part of the EPC protocol is a reference service known as Object Name Service or ONS. Its purpose is to route tag queries to the database of specific tag owners or to the database of back end computer host managers. In other words, there is a system designed and in place for legitimate back end systems to track and trace all objects in an RFID system.
All communication for RFID interrogators and transponders is via an insecure medium. That medium is air, also known as the atmosphere, and sometimes referred to as the environment. In other words, all wireless communication using RFID technology travels through an atmosphere, or an environment, shared by legitimate and illegitimate users or wireless technology alike. The shared medium highlights security and privacy problems for retail consumers of products containing item level RFID tags, whether attached or embedded.
There are two main privacy concerns espoused by privacy proponents and lobbyists. Specifically, these are clandestine tracking and inventorying. As RFID tags respond to reader interrogation without alerting the holder of a tagged item, surreptitious scanning of tags is a serious security threat. Pursuant to EPC protocol each tag always emits a unique identifier. This includes even those tags which protect data with cryptographic algorithms. The result is that a person in possession of an item level object which has a tag attached to it or embedded into it effectively transmits a fixed identifier number to any nearby interrogators. Therefore, tracking the whereabouts of a retail consumer in possession of an RFID tag is easy for those so inclined. This is true even if the unique identifying number is random or carries no intrinsic data. Consider it to be a beacon, like a lighthouse on a pitch black night, which never turns off.